Association of Pulmonary Hypertension with Sickle Cell Disease Subtypes

Abstract

Pulmonary hypertension (PH) is a common complication of sickle cell disease (SD) and a significant cause of morbidity and mortality. PH, measured by Doppler echocardiography and defined as a tricuspid regurgitant jet velocity (TRV) > 2.5 m per second (m/s), is hypothesized to be related to the chronic hemolytic anemia of SD, but causality is unproven. If so, the presence of hemoglobin C, which reduces hemolysis, would be expected to have a reduced likelihood of PH. This study reviewed the prevalence of PH in 3 categories of patients with SD: homozygous S (SS), sickle-beta thalassemia (SB), and SC.Methods: Sickle cell disease patients registered at a state funded community comprehensive care adult sickle cell center were routinely screened for PH by Doppler echocardiography. The presence of PH, the incidence of a related complication, acute chest syndrome (ACS), and baseline hemoglobin (hgb) were reviewed.Results: 16 patients with SC type, 30 with SS and 39 with SB disease underwent screening. The prevalence of PH, ACS and hgb are listed in the table below.Conclusion: SC patients have PH and ACS similar to patients with SS and SB patients. These patients have higher baseline hemoglobin and may have hyperviscosity as a cause of PH and ACS as opposed to hemolytic anemia. Further study of PH and ACS in SC patients is warranted.SCSSSBp valuePH6/16 (38%)12/40 (40%)11/39 (28%)p= NSACS7/16 (44%)10/30 (33%)19/39 (49%)p=NSPH + ACS4/16 (25%)5/30 (17%)4/39 (10%)p=NSACS in PH patients4/6 (67%)5/12 (42%)4/11 (36%)p-=NSHgb10.87.898.57p=0.000